asterisk users - Jan 2006 - T3 Mux and Asterisk Question

I have a T3 coming from my carrier.  From there I want to use an Adtran
mx2800 T1 Mux to break the T3 into 28 T1/PRI which feed into seven quad
T1/PRI equipped servers.

Everything seems very straight forward with the exception of the D
channels for the T1/PRI.

I am not very familiar with large circuits such as T3s.  I know that I
can use one D channel per set of quad port on each server.  So if each
server has a quad port card, I can use one channel as the D channel for
all four spans.

That gives me seven D channels in my setup.  Does anyone know how the
Mux handles these D channels onto the T3?  My guess is the Mux is simple
going to send all of the channels onto the T3 without modifying
anything. 

What I would really like to do is have one D channel coming in on the T3
and have it split between each of the T1/PRI or even better one D
channel per quad (I know Asterisk can do that).  

Is it possible?  If the Adtran mx2800 cannot do it, is there anther
product that can.  I have looked at the RAD Optimux T3 product but have
had great experience with Adtran products.  The price is the same but
the Adtran allows for two controller cards so it seems to have more
built in redundancy.

Any tips would be appreciated.

Thanks,
Steve

On 1/22/06, Steve Totaro <stotaro@totarotechnologies.com>
wrote:
> I have a T3 coming from my carrier.  From there I want to use an Adtran
> mx2800 T1 Mux to break the T3 into 28 T1/PRI which feed into seven quad
> T1/PRI equipped servers.
>
> Everything seems very straight forward with the exception of the D
> channels for the T1/PRI.
>
> I am not very familiar with large circuits such as T3s.  I know that I
> can use one D channel per set of quad port on each server.  So if each
> server has a quad port card, I can use one channel as the D channel for
> all four spans.
>
> That gives me seven D channels in my setup.  Does anyone know how the
> Mux handles these D channels onto the T3?  My guess is the Mux is simple
> going to send all of the channels onto the T3 without modifying
> anything.
>
> What I would really like to do is have one D channel coming in on the T3
> and have it split between each of the T1/PRI or even better one D
> channel per quad (I know Asterisk can do that).
>
> Is it possible?  If the Adtran mx2800 cannot do it, is there anther
> product that can.  I have looked at the RAD Optimux T3 product but have
> had great experience with Adtran products.  The price is the same but
> the Adtran allows for two controller cards so it seems to have more
> built in redundancy.
>
 I haven't any experience with the Adtran mux product line, but have
done a good amount of work with Carrier Access Corp muxes. With most
DS3 muxes, all they are doing is muxing down a DS3 into DS1's. So, you
could be running E&M or PRI through the muxes and you really don't
change anything on your mux because that's the application running
within the loop. The mux doesn't care about that.

 You're not going to be able to have one D channel for the entire mux
- well - you could - but then you'd need a machine that accepted
signaling for the entire trunk group and that's going to be somewhat
difficult with Asterisk and most intel server machines at this point.

 Just keep in mind when you group all of your DS1s on a quad port card
into one D channel, if you lose the loop that's within that D channel,
you've now lost signaling for all 4 of the DS1s in the group. This may
or may not be a problem for you. If you've got a CLEC that's
delivering that DS3 loop to your location by means of LEC leased
access, you shouldn't assume that your DS3 stays a DS3 through from pt
A to pt B. There were more than a couple times I had seen DS1's fail
inside of DS3's at a prior job and it turned out to be something with
a LEC's DACs or something else.

--
Bird's The Word Technologies, Inc.
http://www.btwtech.com/

Your mux will split the DS3 into 28 DS1 (T1) circuits.  They are 
numbered 1 - 28.  You tell your carrier how and where to assign the D 
channels.  The mux does not have anything to do with D channels or 
signaling; the telco's ISDN switch does.

A simple setup would have a D channel on every DS1 based PRI.  That 
is 23 B channels and 1 D channel.  The B channels carry voice and the 
D handles the call set-up.  When you assign a D channel to handle 
more than one PRI it is called NFAS (Non-Facility Associated 
Signaling) and you are creating an NFAS Group.  It is also common 
practice to create a backup D channel for each group in case there is 
a failure with the primary D channel.

I am not sure how Digium or Sangoma cards and drivers handle NFAS but 
that is probably what you should be looking at and communicating that 
to your carrier.

Tom

At 07:42 AM 1/22/2006, you wrote:
>I have a T3 coming from my carrier.  From there I want to use an Adtran
>mx2800 T1 Mux to break the T3 into 28 T1/PRI which feed into seven quad
>T1/PRI equipped servers.
>
>Everything seems very straight forward with the exception of the D
>channels for the T1/PRI.
>
>I am not very familiar with large circuits such as T3s.  I know that I
>can use one D channel per set of quad port on each server.  So if each
>server has a quad port card, I can use one channel as the D channel for
>all four spans.
>
>That gives me seven D channels in my setup.  Does anyone know how the
>Mux handles these D channels onto the T3?  My guess is the Mux is simple
>going to send all of the channels onto the T3 without modifying
>anything.
>
>What I would really like to do is have one D channel coming in on the T3
>and have it split between each of the T1/PRI or even better one D
>channel per quad (I know Asterisk can do that).
>
>Is it possible?  If the Adtran mx2800 cannot do it, is there anther
>product that can.  I have looked at the RAD Optimux T3 product but have
>had great experience with Adtran products.  The price is the same but
>the Adtran allows for two controller cards so it seems to have more
>built in redundancy.
>
>Any tips would be appreciated.
>
>Thanks,
>Steve
>_______________________________________________
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>
>Asterisk-Users mailing list
>To UNSUBSCRIBE or update options visit:
>    http://lists.digium.com/mailman/listinfo/asterisk-users

Thanks for some answers, that is what I thought.  

Asterisk is NFAS capable so I am looking at seven D channels on the T3 I
guess.  I don't want to put a D channel on each T1 or I will lose
several channels that could be used for calls.  

I wonder if there is any way that Asterisk can do NFAS across multiple
servers.  I would put two cards in a box but they will be doing g729
transcoding so I don't want to push it, so it is one per server.

Thanks,
Steve
> 
> Your mux will split the DS3 into 28 DS1 (T1) circuits.  They are
> numbered 1 - 28.  You tell your carrier how and where to assign the D
> channels.  The mux does not have anything to do with D channels or
> signaling; the telco's ISDN switch does.
> 
> A simple setup would have a D channel on every DS1 based PRI.  That
> is 23 B channels and 1 D channel.  The B channels carry voice and the
> D handles the call set-up.  When you assign a D channel to handle
> more than one PRI it is called NFAS (Non-Facility Associated
> Signaling) and you are creating an NFAS Group.  It is also common
> practice to create a backup D channel for each group in case there is
> a failure with the primary D channel.
> 
> I am not sure how Digium or Sangoma cards and drivers handle NFAS but
> that is probably what you should be looking at and communicating that
> to your carrier.
> 
> Tom
> 
> At 07:42 AM 1/22/2006, you wrote:
> >I have a T3 coming from my carrier.  From there I want to use an
Adtran
> >mx2800 T1 Mux to break the T3 into 28 T1/PRI which feed into seven
quad
> >T1/PRI equipped servers.
> >
> >Everything seems very straight forward with the exception of the D
> >channels for the T1/PRI.
> >
> >I am not very familiar with large circuits such as T3s.  I know that
I
> >can use one D channel per set of quad port on each server.  So if
each
> >server has a quad port card, I can use one channel as the D channel
for
> >all four spans.
> >
> >That gives me seven D channels in my setup.  Does anyone know how the
> >Mux handles these D channels onto the T3?  My guess is the Mux is
simple
> >going to send all of the channels onto the T3 without modifying
> >anything.
> >
> >What I would really like to do is have one D channel coming in on the
T3
> >and have it split between each of the T1/PRI or even better one D
> >channel per quad (I know Asterisk can do that).
> >
> >Is it possible?  If the Adtran mx2800 cannot do it, is there anther
> >product that can.  I have looked at the RAD Optimux T3 product but
have
> >had great experience with Adtran products.  The price is the same but
> >the Adtran allows for two controller cards so it seems to have more
> >built in redundancy.
> >
> >Any tips would be appreciated.
> >
> >Thanks,
> >Steve
> >_______________________________________________
> >--Bandwidth and Colocation provided by Easynews.com --
> >
> >Asterisk-Users mailing list
> >To UNSUBSCRIBE or update options visit:
> >    http://lists.digium.com/mailman/listinfo/asterisk-users
> 
> _______________________________________________
> --Bandwidth and Colocation provided by Easynews.com --
> 
> Asterisk-Users mailing list
> To UNSUBSCRIBE or update options visit:
>    http://lists.digium.com/mailman/listinfo/asterisk-users

On Sun, 22 Jan 2006, Steve Totaro wrote:
> I have a T3 coming from my carrier.  From there I want to use an Adtran
> mx2800 T1 Mux to break the T3 into 28 T1/PRI which feed into seven quad
> T1/PRI equipped servers.
> 
> Everything seems very straight forward with the exception of the D
> channels for the T1/PRI.
> 
> I am not very familiar with large circuits such as T3s.  I know that I
> can use one D channel per set of quad port on each server.  So if each
> server has a quad port card, I can use one channel as the D channel for
> all four spans.
> 
> That gives me seven D channels in my setup.  Does anyone know how the
> Mux handles these D channels onto the T3?  My guess is the Mux is simple
> going to send all of the channels onto the T3 without modifying
> anything. 
That's correct. The T1 spans on the DS3 are completely independent of the 
clocking on the DS3. The D-channel and timing is something that will be 
handled by your upstream Telco and the switch that you'll be connecting 
to. Or, your own box.. ;)
 
> What I would really like to do is have one D channel coming in on the T3
> and have it split between each of the T1/PRI or even better one D
> channel per quad (I know Asterisk can do that). 
> 
> Is it possible?
No.
> If the Adtran mx2800 cannot do it, is there anther
> product that can.  I have looked at the RAD Optimux T3 product but have
> had great experience with Adtran products.  The price is the same but
> the Adtran allows for two controller cards so it seems to have more
> built in redundancy.
> 
> Any tips would be appreciated.
Adtran's MX-2800 is our choice for Muxes. They are solid, reliable and 
work well. Adtran's technical support is amazing. When you purchase an 
MX-2800, you are immediately given access to the Adtran Carrier support 
group, which doesn't even blink about sending out an advance replacement 
unit overnight if you ask.

-- 
    Vice President of N2Net, a New Age Consulting Service, Inc. Company
         http://www.n2net.net Where everything clicks into place!
                             KP-216-121-ST

Greg Boehnlein wrote:

(Steve Totaro wrote:)
>>What I would really like to do is have one D channel coming in on the T3
>>and have it split between each of the T1/PRI or even better one D
>>channel per quad (I know Asterisk can do that). 
>>
>>Is it possible?
> 
> 
> No.
Actually, it is, using an Adtran Atlas with a DS3 interface and DS1 
interfaces. Not cheap, but possible.